Search (120 results, page 1 of 6)

  • × theme_ss:"Wissensrepräsentation"
  • × year_i:[2000 TO 2010}
  1. Stojanovic, N.: Ontology-based Information Retrieval : methods and tools for cooperative query answering (2005) 0.26
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    Abstract
    By the explosion of possibilities for a ubiquitous content production, the information overload problem reaches the level of complexity which cannot be managed by traditional modelling approaches anymore. Due to their pure syntactical nature traditional information retrieval approaches did not succeed in treating content itself (i.e. its meaning, and not its representation). This leads to a very low usefulness of the results of a retrieval process for a user's task at hand. In the last ten years ontologies have been emerged from an interesting conceptualisation paradigm to a very promising (semantic) modelling technology, especially in the context of the Semantic Web. From the information retrieval point of view, ontologies enable a machine-understandable form of content description, such that the retrieval process can be driven by the meaning of the content. However, the very ambiguous nature of the retrieval process in which a user, due to the unfamiliarity with the underlying repository and/or query syntax, just approximates his information need in a query, implies a necessity to include the user in the retrieval process more actively in order to close the gap between the meaning of the content and the meaning of a user's query (i.e. his information need). This thesis lays foundation for such an ontology-based interactive retrieval process, in which the retrieval system interacts with a user in order to conceptually interpret the meaning of his query, whereas the underlying domain ontology drives the conceptualisation process. In that way the retrieval process evolves from a query evaluation process into a highly interactive cooperation between a user and the retrieval system, in which the system tries to anticipate the user's information need and to deliver the relevant content proactively. Moreover, the notion of content relevance for a user's query evolves from a content dependent artefact to the multidimensional context-dependent structure, strongly influenced by the user's preferences. This cooperation process is realized as the so-called Librarian Agent Query Refinement Process. In order to clarify the impact of an ontology on the retrieval process (regarding its complexity and quality), a set of methods and tools for different levels of content and query formalisation is developed, ranging from pure ontology-based inferencing to keyword-based querying in which semantics automatically emerges from the results. Our evaluation studies have shown that the possibilities to conceptualize a user's information need in the right manner and to interpret the retrieval results accordingly are key issues for realizing much more meaningful information retrieval systems.
    Content
    Vgl.: http%3A%2F%2Fdigbib.ubka.uni-karlsruhe.de%2Fvolltexte%2Fdocuments%2F1627&ei=tAtYUYrBNoHKtQb3l4GYBw&usg=AFQjCNHeaxKkKU3-u54LWxMNYGXaaDLCGw&sig2=8WykXWQoDKjDSdGtAakH2Q&bvm=bv.44442042,d.Yms.
  2. Hauer, M.: Mehrsprachige semantische Netze leichter entwickeln (2002) 0.03
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    Abstract
    AGI - Information Management Consultants liefern seit nunmehr 16 Jahren eine Software zur Entwicklung von Thesauri und Klassifikationen, ehemals bezeichnet als INDEX, seit zweieinhalb Jahren als IC INDEX neu entwickelt. Solche Terminologien werden oft auch als Glossar, Lexikon, Topic Maps, RDF, semantisches Netz, Systematik, Aktenplan oder Nomenklatur bezeichnet. Die Software erlaubt zwar schon immer, dass solche terminologischen Werke mehrsprachig angelegt sind, doch es gab keine speziellen Werkzeuge, um die Übersetzung zu erleichtern. Die Globalisierung führt zunehmend auch zur Mehrsprachigkeit von Fachterminologien, wie laufende Projekte belegen. In IC INDEX 5.08 wurde deshalb ein spezieller Workflow für die Übersetzung implementiert, der Wortfelder bearbeitet und dabei weitgehend automatisch, aber vom Übersetzer kontrolliert, die richtigen Verbindungen zwischen den Termen in den anderen Sprachen erzeugt. Bereits dieser Workflow beschleunigt wesentlich die Übersetzungstätigkeit. Doch es geht noch schneller: der eTranslation Server von Linguatec generiert automatisch Übersetzungsvorschläge für Deutsch/English und Deutsch/Französisch. Demnächst auch Deutsch/Spanisch und Deutsch/Italienisch. Gerade bei Mehrwortbegriffen, Klassenbezeichnungen und Komposita spielt die automatische Übersetzung gegenüber dem Wörterbuch-Lookup ihre Stärke aus. Der Rückgriff ins Wörterbuch ist selbstverständlich auch implementiert, sowohl auf das Linguatec-Wörterbuch und zusätzlich jedes beliebige über eine URL adressierbare Wörterbuch. Jeder Übersetzungsvorschlag muss vom Terminologie-Entwickler bestätigt werden. Im Rahmen der Oualitätskontrolle haben wir anhand vorliegender mehrsprachiger Thesauri getestet mit dem Ergebnis, dass die automatischen Vorschläge oft gleich und fast immer sehr nahe an der gewünschten Übersetzung waren. Worte, die für durchschnittlich gebildete Menschen nicht mehr verständlich sind, bereiten auch der maschinellen Übersetzung Probleme, z.B. Fachbegriffe aus Medizin, Chemie und anderen Wissenschaften. Aber auch ein Humanübersetzer wäre hier ohne einschlägige Fachausbildung überfordert. Also, ohne Fach- und ohne Sprachkompetenz geht es nicht, aber mit geht es ziemlich flott. IC INDEX basiert auf Lotus Notes & Domino 5.08. Beliebige Relationen zwischen Termen sind zulässig, die ANSI-Normen sind implementiert und um zusätzliche Relationen ergänzt, 26 Relationen gehören zum Lieferumfang. Ausgaben gemäß Topic Maps oder RDF - zwei eng verwandte Normen-werden bei Nachfrage entwickelt. Ausgaben sind in HMTL, XML, eine ansprechende Druckversion unter MS Word 2000 und für verschiedene Search-Engines vorhanden. AGI - Information Management Consultants, Neustadt an der Weinstraße, beraten seit 1983 Unternehmen und Organisationen im dem heute als Knowledge Management bezeichneten Feld. Seit 1994 liefern sie eine umfassende, hochintegrative Lösung: "Information Center" - darin ist IC INDEX ein eigenständiges Modul zur Unterstützung von mehrsprachiger Indexierung und mehrsprachigem semantischem Retrieval. Linguatec, München, ist einstmals aus den linguistischen Forschungslabors von IBM hervorgegangen und ist über den Personal Translator weithin bekannt.
  3. Kreissig, B.: ¬Der neue Brockhaus : Einsatz von Sprachtechnologie und Wissensnetz (2006) 0.02
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    Abstract
    Menschliches Wissen und menschliche Sprache sind aufeinander bezogen und voneinander abhängig. Dies gilt auch und gerade bei den Bemühungen, Sprache und Wissen computergestützt so zu verarbeiten, dass für Menschen nutzbare maschinelle Wissensverarbeitung stattfindet. Jenseits von eher akademischen "Laborversuchen" hat wissenschaftliche Forschungsarbeit auf diesem Gebiet die Verfügbarkeit umfangreicher, gepflegter und sauber codierter Wissensbasen sowohl der verwendeten Sprache als auch des abgebildeten Gegenstands zur Voraussetzung. In einem Forschungsprojekt der Firma Brockhaus Duden Neue Medien GmbH gemeinsam mit namhaften wissenschaftlichen Partnern, u.a. dem Fraunhofer-IPSI, dem IICM der TU Graz, dem IAI der Universität Saarbrücken und dem KNOW-Center, Graz, wurde diese Herausforderung erfolgreich angegangen. Für eine neue digitale Brockhaus-Auflage wurden Informationsrepräsentations- und Retrievaltechniken entwickelt, die nicht auf domänenspezifischen Beschränkungen beruhend den gesamten enzyklopädischen Wissenskreis abdecken. Die entwickelten Formalismen erwiesen sich nicht nur zur Abfrage des enzyklopädischen Wissens in natürlicher Sprache als geeignet, sondern konnten auch darauf basierend neuartige Formen der Visualisierung von Wissenszusammenhängen implementiert werden. Die Ergebnisse zeigen zum einen Möglichkeiten erfolgreichen semantischen Retrievals ohne extensiven Einsatzformaler Metacodierungen, zum anderen weisen sie den Weg und die nächsten Schritte bei der Entwicklung noch leistungsfähigerer Mensch-Maschine-Schnittstellen.
  4. Beppler, F.D.; Fonseca, F.T.; Pacheco, R.C.S.: Hermeneus: an architecture for an ontology-enabled information retrieval (2008) 0.01
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    Abstract
    Ontologies improve IR systems regarding its retrieval and presentation of information, which make the task of finding information more effective, efficient, and interactive. In this paper we argue that ontologies also greatly improve the engineering of such systems. We created a framework that uses ontology to drive the process of engineering an IR system. We developed a prototype that shows how a domain specialist without knowledge in the IR field can build an IR system with interactive components. The resulting system provides support for users not only to find their information needs but also to extend their state of knowledge. This way, our approach to ontology-enabled information retrieval addresses both the engineering aspect described here and also the usability aspect described elsewhere.
    Date
    28.11.2016 12:43:22
  5. Priss, U.: Faceted information representation (2000) 0.01
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    Abstract
    This paper presents an abstract formalization of the notion of "facets". Facets are relational structures of units, relations and other facets selected for a certain purpose. Facets can be used to structure large knowledge representation systems into a hierarchical arrangement of consistent and independent subsystems (facets) that facilitate flexibility and combinations of different viewpoints or aspects. This paper describes the basic notions, facet characteristics and construction mechanisms. It then explicates the theory in an example of a faceted information retrieval system (FaIR)
    Date
    22. 1.2016 17:47:06
  6. Renear, A.H.; Wickett, K.M.; Urban, R.J.; Dubin, D.; Shreeves, S.L.: Collection/item metadata relationships (2008) 0.01
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    Abstract
    Contemporary retrieval systems, which search across collections, usually ignore collection-level metadata. Alternative approaches, exploiting collection-level information, will require an understanding of the various kinds of relationships that can obtain between collection-level and item-level metadata. This paper outlines the problem and describes a project that is developing a logic-based framework for classifying collection/item metadata relationships. This framework will support (i) metadata specification developers defining metadata elements, (ii) metadata creators describing objects, and (iii) system designers implementing systems that take advantage of collection-level metadata. We present three examples of collection/item metadata relationship categories, attribute/value-propagation, value-propagation, and value-constraint and show that even in these simple cases a precise formulation requires modal notions in addition to first-order logic. These formulations are related to recent work in information retrieval and ontology evaluation.
    Source
    Metadata for semantic and social applications : proceedings of the International Conference on Dublin Core and Metadata Applications, Berlin, 22 - 26 September 2008, DC 2008: Berlin, Germany / ed. by Jane Greenberg and Wolfgang Klas
  7. Knorz, G.; Rein, B.: Semantische Suche in einer Hochschulontologie : Ontologie-basiertes Information-Filtering und -Retrieval mit relationalen Datenbanken (2005) 0.01
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    Date
    11. 2.2011 18:22:25
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  8. Knorz, G.; Rein, B.: Semantische Suche in einer Hochschulontologie (2005) 0.01
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    Date
    11. 2.2011 18:22:58
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  9. Kottmann, N.; Studer, T.: Improving semantic query answering (2006) 0.01
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    Abstract
    The retrieval problem is one of the main reasoning tasks for knowledge base systems. Given a knowledge base K and a concept C, the retrieval problem consists of finding all individuals a for which K logically entails C(a). We present an approach to answer retrieval queries over (a restriction of) OWL ontologies. Our solution is based on reducing the retrieval problem to a problem of evaluating an SQL query over a database constructed from the original knowledge base. We provide complete answers to retrieval problems. Still, our system performs very well as is shown by a standard benchmark.
  10. Paralic, J.; Kostial, I.: Ontology-based information retrieval (2003) 0.01
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    Abstract
    In the proposed article a new, ontology-based approach to information retrieval (IR) is presented. The system is based on a domain knowledge representation schema in form of ontology. New resources registered within the system are linked to concepts from this ontology. In such a way resources may be retrieved based on the associations and not only based on partial or exact term matching as the use of vector model presumes In order to evaluate the quality of this retrieval mechanism, experiments to measure retrieval efficiency have been performed with well-known Cystic Fibrosis collection of medical scientific papers. The ontology-based retrieval mechanism has been compared with traditional full text search based on vector IR model as well as with the Latent Semantic Indexing method.
  11. Dobrev, P.; Kalaydjiev, O.; Angelova, G.: From conceptual structures to semantic interoperability of content (2007) 0.00
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    Abstract
    Smart applications behave intelligently because they understand at least partially the context where they operate. To do this, they need not only a formal domain model but also formal descriptions of the data they process and their own operational behaviour. Interoperability of smart applications is based on formalised definitions of all their data and processes. This paper studies the semantic interoperability of data in the case of eLearning and describes an experiment and its assessment. New content is imported into a knowledge-based learning environment without real updates of the original domain model, which is encoded as a knowledge base of conceptual graphs. A component called mediator enables the import by assigning dummy metadata annotations for the imported items. However, some functionality of the original system is lost, when processing the imported content, due to the lack of proper metadata annotation which cannot be associated fully automatically. So the paper presents an interoperability scenario when appropriate content items are viewed from the perspective of the original world and can be (partially) reused there.
    Source
    Conceptual structures: knowledge architectures for smart applications: 15th International Conference on Conceptual Structures, ICCS 2007, Sheffield, UK, July 22 - 27, 2007 ; proceedings. Eds.: U. Priss u.a
  12. Müller, T.: Wissensrepräsentation mit semantischen Netzen im Bereich Luftfahrt (2006) 0.00
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    Abstract
    Es ist ein semantisches Netz für den Gegenstandsbereich Luftfahrt modelliert worden, welches Unternehmensinformationen, Organisationen, Fluglinien, Flughäfen, etc. enthält, Diese sind 10 Hauptkategorien zugeordnet worden, die untergliedert nach Facetten sind. Die Begriffe des Gegenstandsbereiches sind mit 23 unterschiedlichen Relationen verknüpft worden (Z. B.: 'hat Standort in', bietet an, 'ist Homebase von', etc). Der Schwerpunkt der Betrachtung liegt auf dem Unterschied zwischen den drei klassischen Standardrelationen und den zusätzlich eingerichteten Relationen, bezüglich ihrem Nutzen für ein effizientes Retrieval. Die angelegten Kategorien und Relationen sind sowohl für eine kognitive als auch für eine maschinelle Verarbeitung geeignet.
    Date
    26. 9.2006 21:00:22
  13. Yi, M.: Information organization and retrieval using a topic maps-based ontology : results of a task-based evaluation (2008) 0.00
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    Abstract
    As information becomes richer and more complex, alternative information-organization methods are needed to more effectively and efficiently retrieve information from various systems, including the Web. The objective of this study is to explore how a Topic Maps-based ontology approach affects users' searching performance. Forty participants participated in a task-based evaluation where two dependent variables, recall and search time, were measured. The results of this study indicate that a Topic Maps-based ontology information retrieval (TOIR) system has a significant and positive effect on both recall and search time, compared to a thesaurus-based information retrieval (TIR) system. These results suggest that the inclusion of a Topic Maps-based ontology is a beneficial approach to take when designing information retrieval systems.
  14. Starostenko, O.; Rodríguez-Asomoza, J.; Sénchez-López, S.E.; Chévez-Aragón, J.A.: Shape indexing and retrieval : a hybrid approach using ontological description (2008) 0.00
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    Abstract
    This paper presents a novel hybrid approach for visual information retrieval (VIR) that combines shape analysis of objects in image with their indexing by textual descriptions. The principal goal of presented technique is applying Two Segments Turning Function (2STF) proposed by authors for efficient invariant to spatial variations shape processing and implementation of semantic Web approaches for ontology-based user-oriented annotations of multimedia information. In the proposed approach the user's textual queries are converted to image features, which are used for images searching, indexing, interpretation, and retrieval. A decision about similarity between retrieved image and user's query is taken computing the shape convergence to 2STF combining it with matching the ontological annotations of objects in image and providing in this way automatic definition of the machine-understandable semantics. In order to evaluate the proposed approach the Image Retrieval by Ontological Description of Shapes system has been designed and tested using some standard image domains.
  15. Tomassen, S.L.: Research on ontology-driven information retrieval (2006 (?)) 0.00
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    Abstract
    An increasing number of recent information retrieval systems make use of ontologies to help the users clarify their information needs and come up with semantic representations of documents. A particular concern here is the integration of these semantic approaches with traditional search technology. The research presented in this paper examines how ontologies can be efficiently applied to large-scale search systems for the web. We describe how these systems can be enriched with adapted ontologies to provide both an in-depth understanding of the user's needs as well as an easy integration with standard vector-space retrieval systems. The ontology concepts are adapted to the domain terminology by computing a feature vector for each concept. Later, the feature vectors are used to enrich a provided query. The whole retrieval system is under development as part of a larger Semantic Web standardization project for the Norwegian oil & gas sector.
  16. Vallet, D.; Fernández, M.; Castells, P.: ¬An ontology-based information retrieval model (2005) 0.00
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    Abstract
    Semantic search has been one of the motivations of the Semantic Web since it was envisioned. We propose a model for the exploitation of ontologybased KBs to improve search over large document repositories. Our approach includes an ontology-based scheme for the semi-automatic annotation of documents, and a retrieval system. The retrieval model is based on an adaptation of the classic vector-space model, including an annotation weighting algorithm, and a ranking algorithm. Semantic search is combined with keyword-based search to achieve tolerance to KB incompleteness. Our proposal is illustrated with sample experiments showing improvements with respect to keyword-based search, and providing ground for further research and discussion.
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  17. Town, C.: Ontological inference for image and video analysis (2006) 0.00
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    Abstract
    This paper presents an approach to designing and implementing extensible computational models for perceiving systems based on a knowledge-driven joint inference approach. These models can integrate different sources of information both horizontally (multi-modal and temporal fusion) and vertically (bottom-up, top-down) by incorporating prior hierarchical knowledge expressed as an extensible ontology.Two implementations of this approach are presented. The first consists of a content-based image retrieval system that allows users to search image databases using an ontological query language. Queries are parsed using a probabilistic grammar and Bayesian networks to map high-level concepts onto low-level image descriptors, thereby bridging the 'semantic gap' between users and the retrieval system. The second application extends the notion of ontological languages to video event detection. It is shown how effective high-level state and event recognition mechanisms can be learned from a set of annotated training sequences by incorporating syntactic and semantic constraints represented by an ontology.
  18. Tudhope, D.; Hodge, G.: Terminology registries (2007) 0.00
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    Date
    26.12.2011 13:22:07
  19. Haller, S.H.M.: Mappingverfahren zur Wissensorganisation (2002) 0.00
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    Date
    30. 5.2010 16:22:35
  20. Kiryakov, A.; Popov, B.; Terziev, I.; Manov, D.; Ognyanoff, D.: Semantic annotation, indexing, and retrieval (2004) 0.00
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    Abstract
    The Semantic Web realization depends on the availability of a critical mass of metadata for the web content, associated with the respective formal knowledge about the world. We claim that the Semantic Web, at its current stage of development, is in a state of a critical need of metadata generation and usage schemata that are specific, well-defined and easy to understand. This paper introduces our vision for a holistic architecture for semantic annotation, indexing, and retrieval of documents with regard to extensive semantic repositories. A system (called KIM), implementing this concept, is presented in brief and it is used for the purposes of evaluation and demonstration. A particular schema for semantic annotation with respect to real-world entities is proposed. The underlying philosophy is that a practical semantic annotation is impossible without some particular knowledge modelling commitments. Our understanding is that a system for such semantic annotation should be based upon a simple model of real-world entity classes, complemented with extensive instance knowledge. To ensure the efficiency, ease of sharing, and reusability of the metadata, we introduce an upper-level ontology (of about 250 classes and 100 properties), which starts with some basic philosophical distinctions and then goes down to the most common entity types (people, companies, cities, etc.). Thus it encodes many of the domain-independent commonsense concepts and allows straightforward domain-specific extensions. On the basis of the ontology, a large-scale knowledge base of entity descriptions is bootstrapped, and further extended and maintained. Currently, the knowledge bases usually scales between 105 and 106 descriptions. Finally, this paper presents a semantically enhanced information extraction system, which provides automatic semantic annotation with references to classes in the ontology and to instances. The system has been running over a continuously growing document collection (currently about 0.5 million news articles), so it has been under constant testing and evaluation for some time now. On the basis of these semantic annotations, we perform semantic based indexing and retrieval where users can mix traditional information retrieval (IR) queries and ontology-based ones. We argue that such large-scale, fully automatic methods are essential for the transformation of the current largely textual web into a Semantic Web.

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